Currently, KVM ARM/ARM64 only provides in-kernel emulation of Power State and Coordination Interface (PSCI) v0.1.
This patchset aims at providing newer PSCI v0.2 for KVM ARM/ARM64 VCPUs such that it does not break current KVM ARM/ARM64 ABI.
The user space tools (i.e. QEMU or KVMTOOL) will have to explicitly enable KVM_ARM_VCPU_PSCI_0_2 feature using KVM_ARM_VCPU_INIT ioctl for providing PSCI v0.2 to VCPUs.
Changlog:
V11: - Added more comments to uapi/linux/psci.h - Added comment about why we store INTERNAL_FAILURE in r0 (or x0) for SYSTEM_OFF and SYSTEM_RESET emulation
V10: - Updated PSCI_VERSION_xxx defines in uapi/linux/psci.h - Added PSCI_0_2_AFFINITY_LEVEL_xxxx defines in uapi/linux/psci.h - Removed PSCI v0.1 related defines from uapi/linux/psci.h - Inject undefined exception for all types of errors in PSCI emulation (i.e kvm_psci_call(vcpu) < 0) - Removed "inline" attribute of kvm_prepare_system_event() - Store INTERNAL_FAILURE in r0 (or x0) before exiting to userspace - Use MPIDR_LEVEL_BITS in AFFINITY_MASK define - Updated comment in kvm_psci_vcpu_suspend() as-per Marc's suggestion
V9: - Rename undefined PSCI_VER_xxx defines to PSCI_VERSION_xxx defines
V8: - Add #define for possible values of migrate type in uapi/linux/psci.h - Simplified psci_affinity_mask() in psci.c - Update comments in kvm_psci_vcpu_suspend() to indicate that for KVM wakeup events are interrupts. - Unconditionally update r0 (or x0) in kvm_psci_vcpu_on()
V7: - Make uapi/linux/psci.h inline with Ashwin's patch http://www.spinics.net/lists/arm-kernel/msg319090.html - Incorporate Rob's suggestions for uapi/linux/psci.h - Treat CPU_SUSPEND power-down request to be same as standby request. This further simplifies CPU_SUSPEND emulation.
V6: - Introduce uapi/linux/psci.h for sharing PSCI defines between ARM kernel, ARM64 kernel, KVM ARM/ARM64 and user space - Make CPU_SUSPEND emulation similar to WFI emulation
V5: - Have separate last patch to advertise KVM_CAP_ARM_PSCI_0_2 - Use kvm_psci_version() in kvm_psci_vcpu_on() - Return ALREADY_ON for PSCI v0.2 CPU_ON if VCPU is not paused - Remove per-VCPU suspend context - As-per PSCI v0.2 spec, only current CPU can suspend itself
V4: - Implement all mandatory functions required by PSCI v0.2
V3: - Make KVM_ARM_VCPU_PSCI_0_2 feature experiementatl for now so that it fails for user space till all mandatory PSCI v0.2 functions are emulated by KVM ARM/ARM64 - Have separate patch for making KVM_ARM_VCPU_PSCI_0_2 feature available to user space. This patch can be defferred for now
V2: - Don't rename PSCI return values KVM_PSCI_RET_NI and KVM_PSCI_RET_INVAL - Added kvm_psci_version() to get PSCI version available to VCPU - Fixed grammer in Documentation/virtual/kvm/api.txt
V1: - Initial RFC PATCH
Anup Patel (12): KVM: Add capability to advertise PSCI v0.2 support ARM/ARM64: KVM: Add common header for PSCI related defines ARM/ARM64: KVM: Add base for PSCI v0.2 emulation KVM: Documentation: Add info regarding KVM_ARM_VCPU_PSCI_0_2 feature ARM/ARM64: KVM: Make kvm_psci_call() return convention more flexible KVM: Add KVM_EXIT_SYSTEM_EVENT to user space API header ARM/ARM64: KVM: Emulate PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET ARM/ARM64: KVM: Emulate PSCI v0.2 AFFINITY_INFO ARM/ARM64: KVM: Emulate PSCI v0.2 MIGRATE_INFO_TYPE and related functions ARM/ARM64: KVM: Fix CPU_ON emulation for PSCI v0.2 ARM/ARM64: KVM: Emulate PSCI v0.2 CPU_SUSPEND ARM/ARM64: KVM: Advertise KVM_CAP_ARM_PSCI_0_2 to user space
Documentation/virtual/kvm/api.txt | 17 +++ arch/arm/include/asm/kvm_host.h | 2 +- arch/arm/include/asm/kvm_psci.h | 6 +- arch/arm/include/uapi/asm/kvm.h | 10 +- arch/arm/kvm/arm.c | 1 + arch/arm/kvm/handle_exit.c | 10 +- arch/arm/kvm/psci.c | 235 ++++++++++++++++++++++++++++++++++--- arch/arm64/include/asm/kvm_host.h | 2 +- arch/arm64/include/asm/kvm_psci.h | 6 +- arch/arm64/include/uapi/asm/kvm.h | 10 +- arch/arm64/kvm/handle_exit.c | 10 +- include/uapi/linux/Kbuild | 1 + include/uapi/linux/kvm.h | 9 ++ include/uapi/linux/psci.h | 90 ++++++++++++++ 14 files changed, 372 insertions(+), 37 deletions(-) create mode 100644 include/uapi/linux/psci.h
User space (i.e. QEMU or KVMTOOL) should be able to check whether KVM ARM/ARM64 supports in-kernel PSCI v0.2 emulation. For this purpose, we define KVM_CAP_ARM_PSCI_0_2 in KVM user space interface header.
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Acked-by: Christoffer Dall christoffer.dall@linaro.org Acked-by: Marc Zyngier marc.zyngier@arm.com --- include/uapi/linux/kvm.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index a8f4ee5..01c5624 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -743,6 +743,7 @@ struct kvm_ppc_smmu_info { #define KVM_CAP_IOAPIC_POLARITY_IGNORED 97 #define KVM_CAP_ENABLE_CAP_VM 98 #define KVM_CAP_S390_IRQCHIP 99 +#define KVM_CAP_ARM_PSCI_0_2 100
#ifdef KVM_CAP_IRQ_ROUTING
We need a common place to share PSCI related defines among ARM kernel, ARM64 kernel, KVM ARM/ARM64 PSCI emulation, and user space.
We introduce uapi/linux/psci.h for this purpose. This newly added header will be first used by KVM ARM/ARM64 in-kernel PSCI emulation and user space (i.e. QEMU or KVMTOOL).
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org --- include/uapi/linux/Kbuild | 1 + include/uapi/linux/psci.h | 90 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 91 insertions(+) create mode 100644 include/uapi/linux/psci.h
diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild index 6929571..24e9033 100644 --- a/include/uapi/linux/Kbuild +++ b/include/uapi/linux/Kbuild @@ -317,6 +317,7 @@ header-y += ppp-ioctl.h header-y += ppp_defs.h header-y += pps.h header-y += prctl.h +header-y += psci.h header-y += ptp_clock.h header-y += ptrace.h header-y += qnx4_fs.h diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h new file mode 100644 index 0000000..310d83e --- /dev/null +++ b/include/uapi/linux/psci.h @@ -0,0 +1,90 @@ +/* + * ARM Power State and Coordination Interface (PSCI) header + * + * This header holds common PSCI defines and macros shared + * by: ARM kernel, ARM64 kernel, KVM ARM/ARM64 and user space. + * + * Copyright (C) 2014 Linaro Ltd. + * Author: Anup Patel anup.patel@linaro.org + */ + +#ifndef _UAPI_LINUX_PSCI_H +#define _UAPI_LINUX_PSCI_H + +/* + * PSCI v0.1 interface + * + * The PSCI v0.1 function numbers are implementation defined. + * + * Only PSCI return values such as: SUCCESS, NOT_SUPPORTED, + * INVALID_PARAMS, and DENIED defined below are applicable + * to PSCI v0.1. + */ + +/* PSCI v0.2 interface */ +#define PSCI_0_2_FN_BASE 0x84000000 +#define PSCI_0_2_FN(n) (PSCI_0_2_FN_BASE + (n)) +#define PSCI_0_2_64BIT 0x40000000 +#define PSCI_0_2_FN64_BASE \ + (PSCI_0_2_FN_BASE + PSCI_0_2_64BIT) +#define PSCI_0_2_FN64(n) (PSCI_0_2_FN64_BASE + (n)) + +#define PSCI_0_2_FN_PSCI_VERSION PSCI_0_2_FN(0) +#define PSCI_0_2_FN_CPU_SUSPEND PSCI_0_2_FN(1) +#define PSCI_0_2_FN_CPU_OFF PSCI_0_2_FN(2) +#define PSCI_0_2_FN_CPU_ON PSCI_0_2_FN(3) +#define PSCI_0_2_FN_AFFINITY_INFO PSCI_0_2_FN(4) +#define PSCI_0_2_FN_MIGRATE PSCI_0_2_FN(5) +#define PSCI_0_2_FN_MIGRATE_INFO_TYPE PSCI_0_2_FN(6) +#define PSCI_0_2_FN_MIGRATE_INFO_UP_CPU PSCI_0_2_FN(7) +#define PSCI_0_2_FN_SYSTEM_OFF PSCI_0_2_FN(8) +#define PSCI_0_2_FN_SYSTEM_RESET PSCI_0_2_FN(9) + +#define PSCI_0_2_FN64_CPU_SUSPEND PSCI_0_2_FN64(1) +#define PSCI_0_2_FN64_CPU_ON PSCI_0_2_FN64(3) +#define PSCI_0_2_FN64_AFFINITY_INFO PSCI_0_2_FN64(4) +#define PSCI_0_2_FN64_MIGRATE PSCI_0_2_FN64(5) +#define PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU PSCI_0_2_FN64(7) + +/* PSCI v0.2 power state encoding for CPU_SUSPEND function */ +#define PSCI_0_2_POWER_STATE_ID_MASK 0xffff +#define PSCI_0_2_POWER_STATE_ID_SHIFT 0 +#define PSCI_0_2_POWER_STATE_TYPE_SHIFT 16 +#define PSCI_0_2_POWER_STATE_TYPE_MASK \ + (0x1 << PSCI_0_2_POWER_STATE_TYPE_SHIFT) +#define PSCI_0_2_POWER_STATE_AFFL_SHIFT 24 +#define PSCI_0_2_POWER_STATE_AFFL_MASK \ + (0x3 << PSCI_0_2_POWER_STATE_AFFL_SHIFT) + +/* PSCI v0.2 affinity level state returned by AFFINITY_INFO */ +#define PSCI_0_2_AFFINITY_LEVEL_ON 0 +#define PSCI_0_2_AFFINITY_LEVEL_OFF 1 +#define PSCI_0_2_AFFINITY_LEVEL_ON_PENDING 2 + +/* PSCI v0.2 multicore support in Trusted OS returned by MIGRATE_INFO_TYPE */ +#define PSCI_0_2_TOS_UP_MIGRATE 0 +#define PSCI_0_2_TOS_UP_NO_MIGRATE 1 +#define PSCI_0_2_TOS_MP 2 + +/* PSCI version decoding (independent of PSCI version) */ +#define PSCI_VERSION_MAJOR_SHIFT 16 +#define PSCI_VERSION_MINOR_MASK \ + ((1U << PSCI_VERSION_MAJOR_SHIFT) - 1) +#define PSCI_VERSION_MAJOR_MASK ~PSCI_VERSION_MINOR_MASK +#define PSCI_VERSION_MAJOR(ver) \ + (((ver) & PSCI_VERSION_MAJOR_MASK) >> PSCI_VERSION_MAJOR_SHIFT) +#define PSCI_VERSION_MINOR(ver) \ + ((ver) & PSCI_VERSION_MINOR_MASK) + +/* PSCI return values (inclusive of all PSCI versions) */ +#define PSCI_RET_SUCCESS 0 +#define PSCI_RET_NOT_SUPPORTED -1 +#define PSCI_RET_INVALID_PARAMS -2 +#define PSCI_RET_DENIED -3 +#define PSCI_RET_ALREADY_ON -4 +#define PSCI_RET_ON_PENDING -5 +#define PSCI_RET_INTERNAL_FAILURE -6 +#define PSCI_RET_NOT_PRESENT -7 +#define PSCI_RET_DISABLED -8 + +#endif /* _UAPI_LINUX_PSCI_H */
On Tue, Apr 29, 2014 at 11:24:15AM +0530, Anup Patel wrote:
We need a common place to share PSCI related defines among ARM kernel, ARM64 kernel, KVM ARM/ARM64 PSCI emulation, and user space.
We introduce uapi/linux/psci.h for this purpose. This newly added header will be first used by KVM ARM/ARM64 in-kernel PSCI emulation and user space (i.e. QEMU or KVMTOOL).
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Signed-off-by: Ashwin Chaugule ashwin.chaugule@linaro.org
Acked-by: Christoffer Dall christoffer.dall@linaro.org
Currently, the in-kernel PSCI emulation provides PSCI v0.1 interface to VCPUs. This patch extends current in-kernel PSCI emulation to provide PSCI v0.2 interface to VCPUs.
By default, ARM/ARM64 KVM will always provide PSCI v0.1 interface for keeping the ABI backward-compatible.
To select PSCI v0.2 interface for VCPUs, the user space (i.e. QEMU or KVMTOOL) will have to set KVM_ARM_VCPU_PSCI_0_2 feature when doing VCPU init using KVM_ARM_VCPU_INIT ioctl.
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Acked-by: Christoffer Dall christoffer.dall@linaro.org Acked-by: Marc Zyngier marc.zyngier@arm.com --- arch/arm/include/asm/kvm_host.h | 2 +- arch/arm/include/asm/kvm_psci.h | 4 ++ arch/arm/include/uapi/asm/kvm.h | 10 ++-- arch/arm/kvm/psci.c | 93 ++++++++++++++++++++++++++++++------- arch/arm64/include/asm/kvm_host.h | 2 +- arch/arm64/include/asm/kvm_psci.h | 4 ++ arch/arm64/include/uapi/asm/kvm.h | 10 ++-- 7 files changed, 99 insertions(+), 26 deletions(-)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 09af149..193ceaf 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -36,7 +36,7 @@ #define KVM_COALESCED_MMIO_PAGE_OFFSET 1 #define KVM_HAVE_ONE_REG
-#define KVM_VCPU_MAX_FEATURES 1 +#define KVM_VCPU_MAX_FEATURES 2
#include <kvm/arm_vgic.h>
diff --git a/arch/arm/include/asm/kvm_psci.h b/arch/arm/include/asm/kvm_psci.h index 9a83d98..4c0e3e1 100644 --- a/arch/arm/include/asm/kvm_psci.h +++ b/arch/arm/include/asm/kvm_psci.h @@ -18,6 +18,10 @@ #ifndef __ARM_KVM_PSCI_H__ #define __ARM_KVM_PSCI_H__
+#define KVM_ARM_PSCI_0_1 1 +#define KVM_ARM_PSCI_0_2 2 + +int kvm_psci_version(struct kvm_vcpu *vcpu); bool kvm_psci_call(struct kvm_vcpu *vcpu);
#endif /* __ARM_KVM_PSCI_H__ */ diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index ef0c878..e6ebdd3 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -20,6 +20,7 @@ #define __ARM_KVM_H__
#include <linux/types.h> +#include <linux/psci.h> #include <asm/ptrace.h>
#define __KVM_HAVE_GUEST_DEBUG @@ -83,6 +84,7 @@ struct kvm_regs { #define KVM_VGIC_V2_CPU_SIZE 0x2000
#define KVM_ARM_VCPU_POWER_OFF 0 /* CPU is started in OFF state */ +#define KVM_ARM_VCPU_PSCI_0_2 1 /* CPU uses PSCI v0.2 */
struct kvm_vcpu_init { __u32 target; @@ -201,9 +203,9 @@ struct kvm_arch_memory_slot { #define KVM_PSCI_FN_CPU_ON KVM_PSCI_FN(2) #define KVM_PSCI_FN_MIGRATE KVM_PSCI_FN(3)
-#define KVM_PSCI_RET_SUCCESS 0 -#define KVM_PSCI_RET_NI ((unsigned long)-1) -#define KVM_PSCI_RET_INVAL ((unsigned long)-2) -#define KVM_PSCI_RET_DENIED ((unsigned long)-3) +#define KVM_PSCI_RET_SUCCESS PSCI_RET_SUCCESS +#define KVM_PSCI_RET_NI PSCI_RET_NOT_SUPPORTED +#define KVM_PSCI_RET_INVAL PSCI_RET_INVALID_PARAMS +#define KVM_PSCI_RET_DENIED PSCI_RET_DENIED
#endif /* __ARM_KVM_H__ */ diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 448f60e..8c42596c 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -59,7 +59,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) * turned off. */ if (!vcpu || !vcpu->arch.pause) - return KVM_PSCI_RET_INVAL; + return PSCI_RET_INVALID_PARAMS;
target_pc = *vcpu_reg(source_vcpu, 2);
@@ -82,20 +82,60 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) wq = kvm_arch_vcpu_wq(vcpu); wake_up_interruptible(wq);
- return KVM_PSCI_RET_SUCCESS; + return PSCI_RET_SUCCESS; }
-/** - * kvm_psci_call - handle PSCI call if r0 value is in range - * @vcpu: Pointer to the VCPU struct - * - * Handle PSCI calls from guests through traps from HVC instructions. - * The calling convention is similar to SMC calls to the secure world where - * the function number is placed in r0 and this function returns true if the - * function number specified in r0 is withing the PSCI range, and false - * otherwise. - */ -bool kvm_psci_call(struct kvm_vcpu *vcpu) +int kvm_psci_version(struct kvm_vcpu *vcpu) +{ + if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) + return KVM_ARM_PSCI_0_2; + + return KVM_ARM_PSCI_0_1; +} + +static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu) +{ + unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); + unsigned long val; + + switch (psci_fn) { + case PSCI_0_2_FN_PSCI_VERSION: + /* + * Bits[31:16] = Major Version = 0 + * Bits[15:0] = Minor Version = 2 + */ + val = 2; + break; + case PSCI_0_2_FN_CPU_OFF: + kvm_psci_vcpu_off(vcpu); + val = PSCI_RET_SUCCESS; + break; + case PSCI_0_2_FN_CPU_ON: + case PSCI_0_2_FN64_CPU_ON: + val = kvm_psci_vcpu_on(vcpu); + break; + case PSCI_0_2_FN_CPU_SUSPEND: + case PSCI_0_2_FN_AFFINITY_INFO: + case PSCI_0_2_FN_MIGRATE: + case PSCI_0_2_FN_MIGRATE_INFO_TYPE: + case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU: + case PSCI_0_2_FN_SYSTEM_OFF: + case PSCI_0_2_FN_SYSTEM_RESET: + case PSCI_0_2_FN64_CPU_SUSPEND: + case PSCI_0_2_FN64_AFFINITY_INFO: + case PSCI_0_2_FN64_MIGRATE: + case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU: + val = PSCI_RET_NOT_SUPPORTED; + break; + default: + return false; + } + + *vcpu_reg(vcpu, 0) = val; + return true; +} + +static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu) { unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); unsigned long val; @@ -103,16 +143,15 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu) switch (psci_fn) { case KVM_PSCI_FN_CPU_OFF: kvm_psci_vcpu_off(vcpu); - val = KVM_PSCI_RET_SUCCESS; + val = PSCI_RET_SUCCESS; break; case KVM_PSCI_FN_CPU_ON: val = kvm_psci_vcpu_on(vcpu); break; case KVM_PSCI_FN_CPU_SUSPEND: case KVM_PSCI_FN_MIGRATE: - val = KVM_PSCI_RET_NI; + val = PSCI_RET_NOT_SUPPORTED; break; - default: return false; } @@ -120,3 +159,25 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu) *vcpu_reg(vcpu, 0) = val; return true; } + +/** + * kvm_psci_call - handle PSCI call if r0 value is in range + * @vcpu: Pointer to the VCPU struct + * + * Handle PSCI calls from guests through traps from HVC instructions. + * The calling convention is similar to SMC calls to the secure world where + * the function number is placed in r0 and this function returns true if the + * function number specified in r0 is withing the PSCI range, and false + * otherwise. + */ +bool kvm_psci_call(struct kvm_vcpu *vcpu) +{ + switch (kvm_psci_version(vcpu)) { + case KVM_ARM_PSCI_0_2: + return kvm_psci_0_2_call(vcpu); + case KVM_ARM_PSCI_0_1: + return kvm_psci_0_1_call(vcpu); + default: + return false; + }; +} diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 0a1d697..92242ce 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -39,7 +39,7 @@ #include <kvm/arm_vgic.h> #include <kvm/arm_arch_timer.h>
-#define KVM_VCPU_MAX_FEATURES 2 +#define KVM_VCPU_MAX_FEATURES 3
struct kvm_vcpu; int kvm_target_cpu(void); diff --git a/arch/arm64/include/asm/kvm_psci.h b/arch/arm64/include/asm/kvm_psci.h index e301a48..e25c658 100644 --- a/arch/arm64/include/asm/kvm_psci.h +++ b/arch/arm64/include/asm/kvm_psci.h @@ -18,6 +18,10 @@ #ifndef __ARM64_KVM_PSCI_H__ #define __ARM64_KVM_PSCI_H__
+#define KVM_ARM_PSCI_0_1 1 +#define KVM_ARM_PSCI_0_2 2 + +int kvm_psci_version(struct kvm_vcpu *vcpu); bool kvm_psci_call(struct kvm_vcpu *vcpu);
#endif /* __ARM64_KVM_PSCI_H__ */ diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index eaf54a3..e6471da 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -31,6 +31,7 @@ #define KVM_NR_SPSR 5
#ifndef __ASSEMBLY__ +#include <linux/psci.h> #include <asm/types.h> #include <asm/ptrace.h>
@@ -77,6 +78,7 @@ struct kvm_regs {
#define KVM_ARM_VCPU_POWER_OFF 0 /* CPU is started in OFF state */ #define KVM_ARM_VCPU_EL1_32BIT 1 /* CPU running a 32bit VM */ +#define KVM_ARM_VCPU_PSCI_0_2 2 /* CPU uses PSCI v0.2 */
struct kvm_vcpu_init { __u32 target; @@ -186,10 +188,10 @@ struct kvm_arch_memory_slot { #define KVM_PSCI_FN_CPU_ON KVM_PSCI_FN(2) #define KVM_PSCI_FN_MIGRATE KVM_PSCI_FN(3)
-#define KVM_PSCI_RET_SUCCESS 0 -#define KVM_PSCI_RET_NI ((unsigned long)-1) -#define KVM_PSCI_RET_INVAL ((unsigned long)-2) -#define KVM_PSCI_RET_DENIED ((unsigned long)-3) +#define KVM_PSCI_RET_SUCCESS PSCI_RET_SUCCESS +#define KVM_PSCI_RET_NI PSCI_RET_NOT_SUPPORTED +#define KVM_PSCI_RET_INVAL PSCI_RET_INVALID_PARAMS +#define KVM_PSCI_RET_DENIED PSCI_RET_DENIED
#endif
We have in-kernel emulation of PSCI v0.2 in KVM ARM/ARM64. To provide PSCI v0.2 interface to VCPUs, we have to enable KVM_ARM_VCPU_PSCI_0_2 feature when doing KVM_ARM_VCPU_INIT ioctl.
The patch updates documentation of KVM_ARM_VCPU_INIT ioctl to provide info regarding KVM_ARM_VCPU_PSCI_0_2 feature.
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Acked-by: Christoffer Dall christoffer.dall@linaro.org Acked-by: Marc Zyngier marc.zyngier@arm.com --- Documentation/virtual/kvm/api.txt | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index a9380ba5..6dc1db5 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2376,6 +2376,8 @@ Possible features: Depends on KVM_CAP_ARM_PSCI. - KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode. Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only). + - KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 for the CPU. + Depends on KVM_CAP_ARM_PSCI_0_2.
4.83 KVM_ARM_PREFERRED_TARGET
Currently, the kvm_psci_call() returns 'true' or 'false' based on whether the PSCI function call was handled successfully or not. This does not help us emulate system-level PSCI functions where the actual emulation work will be done by user space (QEMU or KVMTOOL). Examples of such system-level PSCI functions are: PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET.
This patch updates kvm_psci_call() to return three types of values: 1) > 0 (success) 2) = 0 (success but exit to user space) 3) < 0 (errors)
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Reviewed-by: Christoffer Dall christoffer.dall@linaro.org Acked-by: Marc Zyngier marc.zyngier@arm.com --- arch/arm/include/asm/kvm_psci.h | 2 +- arch/arm/kvm/handle_exit.c | 10 +++++++--- arch/arm/kvm/psci.c | 28 ++++++++++++++++------------ arch/arm64/include/asm/kvm_psci.h | 2 +- arch/arm64/kvm/handle_exit.c | 10 +++++++--- 5 files changed, 32 insertions(+), 20 deletions(-)
diff --git a/arch/arm/include/asm/kvm_psci.h b/arch/arm/include/asm/kvm_psci.h index 4c0e3e1..6bda945 100644 --- a/arch/arm/include/asm/kvm_psci.h +++ b/arch/arm/include/asm/kvm_psci.h @@ -22,6 +22,6 @@ #define KVM_ARM_PSCI_0_2 2
int kvm_psci_version(struct kvm_vcpu *vcpu); -bool kvm_psci_call(struct kvm_vcpu *vcpu); +int kvm_psci_call(struct kvm_vcpu *vcpu);
#endif /* __ARM_KVM_PSCI_H__ */ diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c index 0de91fc..4c979d4 100644 --- a/arch/arm/kvm/handle_exit.c +++ b/arch/arm/kvm/handle_exit.c @@ -38,14 +38,18 @@ static int handle_svc_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) { + int ret; + trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0), kvm_vcpu_hvc_get_imm(vcpu));
- if (kvm_psci_call(vcpu)) + ret = kvm_psci_call(vcpu); + if (ret < 0) { + kvm_inject_undefined(vcpu); return 1; + }
- kvm_inject_undefined(vcpu); - return 1; + return ret; }
static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 8c42596c..14e6fa6 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -93,7 +93,7 @@ int kvm_psci_version(struct kvm_vcpu *vcpu) return KVM_ARM_PSCI_0_1; }
-static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu) +static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) { unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); unsigned long val; @@ -128,14 +128,14 @@ static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu) val = PSCI_RET_NOT_SUPPORTED; break; default: - return false; + return -EINVAL; }
*vcpu_reg(vcpu, 0) = val; - return true; + return 1; }
-static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu) +static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) { unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); unsigned long val; @@ -153,11 +153,11 @@ static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu) val = PSCI_RET_NOT_SUPPORTED; break; default: - return false; + return -EINVAL; }
*vcpu_reg(vcpu, 0) = val; - return true; + return 1; }
/** @@ -165,12 +165,16 @@ static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu) * @vcpu: Pointer to the VCPU struct * * Handle PSCI calls from guests through traps from HVC instructions. - * The calling convention is similar to SMC calls to the secure world where - * the function number is placed in r0 and this function returns true if the - * function number specified in r0 is withing the PSCI range, and false - * otherwise. + * The calling convention is similar to SMC calls to the secure world + * where the function number is placed in r0. + * + * This function returns: > 0 (success), 0 (success but exit to user + * space), and < 0 (errors) + * + * Errors: + * -EINVAL: Unrecognized PSCI function */ -bool kvm_psci_call(struct kvm_vcpu *vcpu) +int kvm_psci_call(struct kvm_vcpu *vcpu) { switch (kvm_psci_version(vcpu)) { case KVM_ARM_PSCI_0_2: @@ -178,6 +182,6 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu) case KVM_ARM_PSCI_0_1: return kvm_psci_0_1_call(vcpu); default: - return false; + return -EINVAL; }; } diff --git a/arch/arm64/include/asm/kvm_psci.h b/arch/arm64/include/asm/kvm_psci.h index e25c658..bc39e55 100644 --- a/arch/arm64/include/asm/kvm_psci.h +++ b/arch/arm64/include/asm/kvm_psci.h @@ -22,6 +22,6 @@ #define KVM_ARM_PSCI_0_2 2
int kvm_psci_version(struct kvm_vcpu *vcpu); -bool kvm_psci_call(struct kvm_vcpu *vcpu); +int kvm_psci_call(struct kvm_vcpu *vcpu);
#endif /* __ARM64_KVM_PSCI_H__ */ diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 7bc41ea..182415e 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -30,11 +30,15 @@ typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) { - if (kvm_psci_call(vcpu)) + int ret; + + ret = kvm_psci_call(vcpu); + if (ret < 0) { + kvm_inject_undefined(vcpu); return 1; + }
- kvm_inject_undefined(vcpu); - return 1; + return ret; }
static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
Currently, we don't have an exit reason to notify user space about a system-level event (for e.g. system reset or shutdown) triggered by the VCPU. This patch adds exit reason KVM_EXIT_SYSTEM_EVENT for this purpose. We can also inform user space about the 'type' and architecture specific 'flags' of a system-level event using the kvm_run structure.
This newly added KVM_EXIT_SYSTEM_EVENT will be used by KVM ARM/ARM64 in-kernel PSCI v0.2 support to reset/shutdown VMs.
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Reviewed-by: Christoffer Dall christoffer.dall@linaro.org Reviewed-by: Marc Zyngier marc.zyngier@arm.com --- Documentation/virtual/kvm/api.txt | 15 +++++++++++++++ include/uapi/linux/kvm.h | 8 ++++++++ 2 files changed, 23 insertions(+)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 6dc1db5..c02d725 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2740,6 +2740,21 @@ It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an external interrupt has just been delivered into the guest. User space should put the acknowledged interrupt vector into the 'epr' field.
+ /* KVM_EXIT_SYSTEM_EVENT */ + struct { +#define KVM_SYSTEM_EVENT_SHUTDOWN 1 +#define KVM_SYSTEM_EVENT_RESET 2 + __u32 type; + __u64 flags; + } system_event; + +If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered +a system-level event using some architecture specific mechanism (hypercall +or some special instruction). In case of ARM/ARM64, this is triggered using +HVC instruction based PSCI call from the vcpu. The 'type' field describes +the system-level event type. The 'flags' field describes architecture +specific flags for the system-level event. + /* Fix the size of the union. */ char padding[256]; }; diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 01c5624..e86c36a 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -171,6 +171,7 @@ struct kvm_pit_config { #define KVM_EXIT_WATCHDOG 21 #define KVM_EXIT_S390_TSCH 22 #define KVM_EXIT_EPR 23 +#define KVM_EXIT_SYSTEM_EVENT 24
/* For KVM_EXIT_INTERNAL_ERROR */ /* Emulate instruction failed. */ @@ -301,6 +302,13 @@ struct kvm_run { struct { __u32 epr; } epr; + /* KVM_EXIT_SYSTEM_EVENT */ + struct { +#define KVM_SYSTEM_EVENT_SHUTDOWN 1 +#define KVM_SYSTEM_EVENT_RESET 2 + __u32 type; + __u64 flags; + } system_event; /* Fix the size of the union. */ char padding[256]; };
The PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET functions are system-level functions hence cannot be fully emulated by in-kernel PSCI emulation code.
To tackle this, we forward PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET function calls from vcpu to user space (i.e. QEMU or KVMTOOL) via kvm_run structure using KVM_EXIT_SYSTEM_EVENT exit reasons.
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Reviewed-by: Christoffer Dall christoffer.dall@linaro.org Acked-by: Marc Zyngier marc.zyngier@arm.com --- arch/arm/kvm/psci.c | 46 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 43 insertions(+), 3 deletions(-)
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 14e6fa6..5936213 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -85,6 +85,23 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) return PSCI_RET_SUCCESS; }
+static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type) +{ + memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); + vcpu->run->system_event.type = type; + vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT; +} + +static void kvm_psci_system_off(struct kvm_vcpu *vcpu) +{ + kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN); +} + +static void kvm_psci_system_reset(struct kvm_vcpu *vcpu) +{ + kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET); +} + int kvm_psci_version(struct kvm_vcpu *vcpu) { if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) @@ -95,6 +112,7 @@ int kvm_psci_version(struct kvm_vcpu *vcpu)
static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) { + int ret = 1; unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); unsigned long val;
@@ -114,13 +132,35 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) case PSCI_0_2_FN64_CPU_ON: val = kvm_psci_vcpu_on(vcpu); break; + case PSCI_0_2_FN_SYSTEM_OFF: + kvm_psci_system_off(vcpu); + /* + * We should'nt be going back to guest VCPU after + * receiving SYSTEM_OFF request. + * + * If user space accidently/deliberately resumes + * guest VCPU after SYSTEM_OFF request then guest + * VCPU should see internal failure from PSCI return + * value. To achieve this, we preload r0 (or x0) with + * PSCI return value INTERNAL_FAILURE. + */ + val = PSCI_RET_INTERNAL_FAILURE; + ret = 0; + break; + case PSCI_0_2_FN_SYSTEM_RESET: + kvm_psci_system_reset(vcpu); + /* + * Same reason as SYSTEM_OFF for preloading r0 (or x0) + * with PSCI return value INTERNAL_FAILURE. + */ + val = PSCI_RET_INTERNAL_FAILURE; + ret = 0; + break; case PSCI_0_2_FN_CPU_SUSPEND: case PSCI_0_2_FN_AFFINITY_INFO: case PSCI_0_2_FN_MIGRATE: case PSCI_0_2_FN_MIGRATE_INFO_TYPE: case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU: - case PSCI_0_2_FN_SYSTEM_OFF: - case PSCI_0_2_FN_SYSTEM_RESET: case PSCI_0_2_FN64_CPU_SUSPEND: case PSCI_0_2_FN64_AFFINITY_INFO: case PSCI_0_2_FN64_MIGRATE: @@ -132,7 +172,7 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) }
*vcpu_reg(vcpu, 0) = val; - return 1; + return ret; }
static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
This patch adds emulation of PSCI v0.2 AFFINITY_INFO function call for KVM ARM/ARM64. This is a VCPU-level function call which will be used to determine current state of given affinity level.
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Reviewed-by: Christoffer Dall christoffer.dall@linaro.org Acked-by: Marc Zyngier marc.zyngier@arm.com --- arch/arm/kvm/psci.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 50 insertions(+), 2 deletions(-)
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 5936213..3b6a0cf 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -27,6 +27,16 @@ * as described in ARM document number ARM DEN 0022A. */
+#define AFFINITY_MASK(level) ~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1) + +static unsigned long psci_affinity_mask(unsigned long affinity_level) +{ + if (affinity_level <= 3) + return MPIDR_HWID_BITMASK & AFFINITY_MASK(affinity_level); + + return 0; +} + static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) { vcpu->arch.pause = true; @@ -85,6 +95,42 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) return PSCI_RET_SUCCESS; }
+static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu) +{ + int i; + unsigned long mpidr; + unsigned long target_affinity; + unsigned long target_affinity_mask; + unsigned long lowest_affinity_level; + struct kvm *kvm = vcpu->kvm; + struct kvm_vcpu *tmp; + + target_affinity = *vcpu_reg(vcpu, 1); + lowest_affinity_level = *vcpu_reg(vcpu, 2); + + /* Determine target affinity mask */ + target_affinity_mask = psci_affinity_mask(lowest_affinity_level); + if (!target_affinity_mask) + return PSCI_RET_INVALID_PARAMS; + + /* Ignore other bits of target affinity */ + target_affinity &= target_affinity_mask; + + /* + * If one or more VCPU matching target affinity are running + * then ON else OFF + */ + kvm_for_each_vcpu(i, tmp, kvm) { + mpidr = kvm_vcpu_get_mpidr(tmp); + if (((mpidr & target_affinity_mask) == target_affinity) && + !tmp->arch.pause) { + return PSCI_0_2_AFFINITY_LEVEL_ON; + } + } + + return PSCI_0_2_AFFINITY_LEVEL_OFF; +} + static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type) { memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); @@ -132,6 +178,10 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) case PSCI_0_2_FN64_CPU_ON: val = kvm_psci_vcpu_on(vcpu); break; + case PSCI_0_2_FN_AFFINITY_INFO: + case PSCI_0_2_FN64_AFFINITY_INFO: + val = kvm_psci_vcpu_affinity_info(vcpu); + break; case PSCI_0_2_FN_SYSTEM_OFF: kvm_psci_system_off(vcpu); /* @@ -157,12 +207,10 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) ret = 0; break; case PSCI_0_2_FN_CPU_SUSPEND: - case PSCI_0_2_FN_AFFINITY_INFO: case PSCI_0_2_FN_MIGRATE: case PSCI_0_2_FN_MIGRATE_INFO_TYPE: case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU: case PSCI_0_2_FN64_CPU_SUSPEND: - case PSCI_0_2_FN64_AFFINITY_INFO: case PSCI_0_2_FN64_MIGRATE: case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU: val = PSCI_RET_NOT_SUPPORTED;
This patch adds emulation of PSCI v0.2 MIGRATE, MIGRATE_INFO_TYPE, and MIGRATE_INFO_UP_CPU function calls for KVM ARM/ARM64.
KVM ARM/ARM64 being a hypervisor (and not a Trusted OS), we cannot provide this functions hence we emulate these functions in following way: 1. MIGRATE - Returns "Not Supported" 2. MIGRATE_INFO_TYPE - Return 2 i.e. Trusted OS is not present 3. MIGRATE_INFO_UP_CPU - Returns "Not Supported"
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Reviewed-by: Christoffer Dall christoffer.dall@linaro.org Acked-by: Marc Zyngier marc.zyngier@arm.com --- arch/arm/kvm/psci.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-)
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 3b6a0cf..cce901a 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -182,6 +182,22 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) case PSCI_0_2_FN64_AFFINITY_INFO: val = kvm_psci_vcpu_affinity_info(vcpu); break; + case PSCI_0_2_FN_MIGRATE: + case PSCI_0_2_FN64_MIGRATE: + val = PSCI_RET_NOT_SUPPORTED; + break; + case PSCI_0_2_FN_MIGRATE_INFO_TYPE: + /* + * Trusted OS is MP hence does not require migration + * or + * Trusted OS is not present + */ + val = PSCI_0_2_TOS_MP; + break; + case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU: + case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU: + val = PSCI_RET_NOT_SUPPORTED; + break; case PSCI_0_2_FN_SYSTEM_OFF: kvm_psci_system_off(vcpu); /* @@ -207,12 +223,7 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) ret = 0; break; case PSCI_0_2_FN_CPU_SUSPEND: - case PSCI_0_2_FN_MIGRATE: - case PSCI_0_2_FN_MIGRATE_INFO_TYPE: - case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU: case PSCI_0_2_FN64_CPU_SUSPEND: - case PSCI_0_2_FN64_MIGRATE: - case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU: val = PSCI_RET_NOT_SUPPORTED; break; default:
As-per PSCI v0.2, the source CPU provides physical address of "entry point" and "context id" for starting a target CPU. Also, if target CPU is already running then we should return ALREADY_ON.
Current emulation of CPU_ON function does not consider physical address of "context id" and returns INVALID_PARAMETERS if target CPU is already running.
This patch updates kvm_psci_vcpu_on() such that it works for both PSCI v0.1 and PSCI v0.2.
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Reviewed-by: Christoffer Dall christoffer.dall@linaro.org Acked-by: Marc Zyngier marc.zyngier@arm.com --- arch/arm/kvm/psci.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index cce901a..1067579 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -48,6 +48,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) struct kvm_vcpu *vcpu = NULL, *tmp; wait_queue_head_t *wq; unsigned long cpu_id; + unsigned long context_id; unsigned long mpidr; phys_addr_t target_pc; int i; @@ -68,10 +69,17 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) * Make sure the caller requested a valid CPU and that the CPU is * turned off. */ - if (!vcpu || !vcpu->arch.pause) + if (!vcpu) return PSCI_RET_INVALID_PARAMS; + if (!vcpu->arch.pause) { + if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1) + return PSCI_RET_ALREADY_ON; + else + return PSCI_RET_INVALID_PARAMS; + }
target_pc = *vcpu_reg(source_vcpu, 2); + context_id = *vcpu_reg(source_vcpu, 3);
kvm_reset_vcpu(vcpu);
@@ -86,6 +94,11 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) kvm_vcpu_set_be(vcpu);
*vcpu_pc(vcpu) = target_pc; + /* + * NOTE: We always update r0 (or x0) because for PSCI v0.1 + * the general puspose registers are undefined upon CPU_ON. + */ + *vcpu_reg(vcpu, 0) = context_id; vcpu->arch.pause = false; smp_mb(); /* Make sure the above is visible */
This patch adds emulation of PSCI v0.2 CPU_SUSPEND function call for KVM ARM/ARM64. This is a CPU-level function call which can suspend current CPU or current CPU cluster. We don't have VCPU clusters in KVM so we only suspend the current VCPU.
The CPU_SUSPEND emulation is not tested much because currently there is no CPUIDLE driver in Linux kernel that uses PSCI CPU_SUSPEND. The PSCI CPU_SUSPEND implementation in ARM64 kernel was tested using a Simple CPUIDLE driver which is not published due to unstable DT-bindings for PSCI. (For more info, http://lwn.net/Articles/574950/)
For simplicity, we implement CPU_SUSPEND emulation similar to WFI (Wait-for-interrupt) emulation and we also treat power-down request to be same as stand-by request. This is consistent with section 5.4.1 and section 5.4.2 of PSCI v0.2 specification.
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Acked-by: Christoffer Dall christoffer.dall@linaro.org Acked-by: Marc Zyngier marc.zyngier@arm.com --- arch/arm/kvm/psci.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-)
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 1067579..09cf377 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -37,6 +37,26 @@ static unsigned long psci_affinity_mask(unsigned long affinity_level) return 0; }
+static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu) +{ + /* + * NOTE: For simplicity, we make VCPU suspend emulation to be + * same-as WFI (Wait-for-interrupt) emulation. + * + * This means for KVM the wakeup events are interrupts and + * this is consistent with intended use of StateID as described + * in section 5.4.1 of PSCI v0.2 specification (ARM DEN 0022A). + * + * Further, we also treat power-down request to be same as + * stand-by request as-per section 5.4.2 clause 3 of PSCI v0.2 + * specification (ARM DEN 0022A). This means all suspend states + * for KVM will preserve the register state. + */ + kvm_vcpu_block(vcpu); + + return PSCI_RET_SUCCESS; +} + static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) { vcpu->arch.pause = true; @@ -183,6 +203,10 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) */ val = 2; break; + case PSCI_0_2_FN_CPU_SUSPEND: + case PSCI_0_2_FN64_CPU_SUSPEND: + val = kvm_psci_vcpu_suspend(vcpu); + break; case PSCI_0_2_FN_CPU_OFF: kvm_psci_vcpu_off(vcpu); val = PSCI_RET_SUCCESS; @@ -235,10 +259,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) val = PSCI_RET_INTERNAL_FAILURE; ret = 0; break; - case PSCI_0_2_FN_CPU_SUSPEND: - case PSCI_0_2_FN64_CPU_SUSPEND: - val = PSCI_RET_NOT_SUPPORTED; - break; default: return -EINVAL; }
We have PSCI v0.2 emulation available in KVM ARM/ARM64 hence advertise this to user space (i.e. QEMU or KVMTOOL) via KVM_CHECK_EXTENSION ioctl.
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Acked-by: Christoffer Dall christoffer.dall@linaro.org Acked-by: Marc Zyngier marc.zyngier@arm.com --- arch/arm/kvm/arm.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index f0e50a0..3c82b37 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -197,6 +197,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_DESTROY_MEMORY_REGION_WORKS: case KVM_CAP_ONE_REG: case KVM_CAP_ARM_PSCI: + case KVM_CAP_ARM_PSCI_0_2: r = 1; break; case KVM_CAP_COALESCED_MMIO:
On Tue, Apr 29, 2014 at 11:24:13AM +0530, Anup Patel wrote:
Currently, KVM ARM/ARM64 only provides in-kernel emulation of Power State and Coordination Interface (PSCI) v0.1.
This patchset aims at providing newer PSCI v0.2 for KVM ARM/ARM64 VCPUs such that it does not break current KVM ARM/ARM64 ABI.
The user space tools (i.e. QEMU or KVMTOOL) will have to explicitly enable KVM_ARM_VCPU_PSCI_0_2 feature using KVM_ARM_VCPU_INIT ioctl for providing PSCI v0.2 to VCPUs.
I feel like this is ready to queue for the next merge window. Last chance to object.
-Christoffer
On 29/04/14 20:44, Christoffer Dall wrote:
On Tue, Apr 29, 2014 at 11:24:13AM +0530, Anup Patel wrote:
Currently, KVM ARM/ARM64 only provides in-kernel emulation of Power State and Coordination Interface (PSCI) v0.1.
This patchset aims at providing newer PSCI v0.2 for KVM ARM/ARM64 VCPUs such that it does not break current KVM ARM/ARM64 ABI.
The user space tools (i.e. QEMU or KVMTOOL) will have to explicitly enable KVM_ARM_VCPU_PSCI_0_2 feature using KVM_ARM_VCPU_INIT ioctl for providing PSCI v0.2 to VCPUs.
I feel like this is ready to queue for the next merge window. Last chance to object.
Looks OK to me.
M.
On Wed, Apr 30, 2014 at 10:56:41AM +0100, Marc Zyngier wrote:
On 29/04/14 20:44, Christoffer Dall wrote:
On Tue, Apr 29, 2014 at 11:24:13AM +0530, Anup Patel wrote:
Currently, KVM ARM/ARM64 only provides in-kernel emulation of Power State and Coordination Interface (PSCI) v0.1.
This patchset aims at providing newer PSCI v0.2 for KVM ARM/ARM64 VCPUs such that it does not break current KVM ARM/ARM64 ABI.
The user space tools (i.e. QEMU or KVMTOOL) will have to explicitly enable KVM_ARM_VCPU_PSCI_0_2 feature using KVM_ARM_VCPU_INIT ioctl for providing PSCI v0.2 to VCPUs.
I feel like this is ready to queue for the next merge window. Last chance to object.
Looks OK to me.
Applied to queue. Note that KVM_CAP_ARM_PSCI_0_2 is now defined to 102 after rebasing the patch set onto kvm/next.
Thanks, -Christoffer
linaro-kernel@lists.linaro.org
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Anup Patel -
Christoffer Dall -
Marc Zyngier